The brewing of beer and other alcoholic beverages is an ancient art. The brewing of beer using cask fermentation systems is disclosed in the following references. U.S. Pat. No. 504,145 to Zwietusch discloses closed loop manufacturing of beer using casks in which a component of the loop, pipe r, provides for pressure equalization as beer flows from a cask A through a filter apparatus D into a cask C. U.S. Pat. No. 485,012 to Kreusler discloses routing carbonic-acid (CO.sub.2) gas that would otherwise escape to the atmosphere carrying volatile flavor components with it from a first series of interconnected casks to a second series of interconnected casks. The second series of interconnected casks contains a fluid not saturated or fully impregnated with carbonic-acid gas. The contents of the two series of casks are then intermixed. U.S. Pat. No. 490,056 to Zwietusch discloses another closed loop beer making system that incorporates the use of casks. Specifically, beer from casks labeled A is fed through a filter and into casks labeled C, under a first pressure and against a counter pressure which is greater than the inherent pressure exerted by the carbonic-acid gas within the beer, but less than the first pressure. U.S. Pat. No. 1,099,746 to Heuser discloses using chip casks in a closed loop system.
The use of the "Burton-Union" in England in the last century is known. The Burton-Union utilized 154 gallon oak barrels linked together in rows (a "Union") of pairs. A swan-neck tube from the bung hole of each barrel led to an open trough, or "barm-back," that ran the length of the 12 rows, centered above the barrels. At one end of the trough, and a few inches lower, sat a feeder which led to side rods on either side of the Union and which ran the length of the 12 rows and made connections to each barrel via side taps. The process began with fermenting wort being transferred to the Union after spending 30-50 hours in a primary fermenter. Once in the Union, the CO.sub.2 produced in the barrels forced yeast and beer up through the swan-neck and into the open barm-back. The open barm-back, at a slight decline and attemporated, allowed the yeast to settle, while beer ran to the feeder and back to the barrels via the side rods under the force of gravity. Eventually most of the yeast settled into the open barm-back and fermentation ceased. The result was a "cleansing," or a separation of the yeast from the beer, and excellent pitching yeast for further brews. One hundred years later, very few if any brewers still use the Burton Union. The demise of the Union is explainable by the brewing industry's increasing reliance on more sanitary fermentation materials such as stainless steel. In contrast, wood is more absorbent and therefore more difficult to properly clean and sanitize when compared to stainless steel. Thus, despite the unique flavors obtained through wooden barrel fermentation, higher maintenance and cleaning costs forced the end of a great tradition.
Accordingly, there is a need for an apparatus and methods for brewing beer which utilizes wooden barrels to impart a pleasant flavor to the beer that a metal container or container of another type of material would not provide. There is also a need to provide a modern, sanitary, closed system for transferring the fermenting beer to and from the wooden barrels in the process off cleansing the beer during wooden barrel fermentation.